1. Field of the Invention
The present invention relates to an image reading apparatus for reading an image recorded on a photographic film and, more particularly, to an image reading apparatus in which light is irradiated from a light source to a photographic film supported by a film carrier via an optical waveguide and an image can be read from a plurality of types of photographic films of different sizes or the like.
2. Description of the Related Art
In recent years, there have been proposed photographic processing methods in which a film image recorded on a photographic film is brokendown into component colors of red, green and blue, to be read, and then, the image data obtained by the reading is subjected to a variety of image processings such as correction, and the image then recorded on a recording material, displayed on a display unit, or the like. Some image reading apparatuses in which such photographic processing methods are implemented are provided with a film carrier, a mirror box and a lens unit. The film carrier is detachably disposed in the apparatus body and supports a photographic film loaded from the outside on an optical axis of the lens unit. The mirror box to be used in combination with the film carrier is previously disposed in the apparatus body. The mirror box includes an incident light portion and a light emitting portion connected via a waveguide, in which light incident into the incident light portion from a light source such as a halogen lamp is guided to the light emitting portion by the waveguide, and then, the light emitted from the light emitting portion is irradiated onto the photographic film which has been carried to a predetermined position by the film carrier. The lens unit is adapted to focus transmitted light or reflected light (hereinafter collectively referred to as transmitted light) from the photographic film on a reading sensor such as a line CCD (charge coupled device) or an area CCD, which photoelectrically converts the transmitted light which is formed in an image into an electric signal and outputs the electric signal corresponding to a film image.
Since in the above-described conventional image reading apparatus it is necessary to make the center beam of the transmitted light transmitting the film image of the photographic film accord with the optical axis of the lens unit constructed as an image forming optical system with a high degree of accuracy, the light source, the mirror box and the film carrier are disposed in such a manner that their positions are adjustable in a direction perpendicular to the optical axis of the lens unit (hereinafter referred to as an optical axis adjusting direction). Consequently, when the conventional image reading apparatus performs an optical axis adjusting operation to make the center beam of the transmitted light from the photographic film accord with the optical axis of the lens unit, the position of the mirror box is adjusted in the optical axis adjusting direction in such a manner as to make the center beam of scattered light emitted from the light emitting portion of the mirror box accord with the optical axis of the lens unit. The position of the light source is then adjusted in the optical axis adjusting direction in such a manner as to maximize the amount of the light incident on the mirror box and to minimize illumination unevenness, and further, the position of the film carrier is adjusted in the optical axis adjusting direction in such a manner that the optical axis of the lens unit passes through the center of an image recorded region (frame) of the photographic film.
Moreover, the above-described photographic processing method of the image reading apparatus has the advantage of giving free control of the quality of an image to be recorded by image processing of the image data in comparison with the conventional photographic processing method in which a film image is recorded on photographic paper by surface exposure.
Some of the image reading apparatuses, in which the above-described photographic processing methods are implemented, may be provided with a film carrier detachably disposed in the apparatus body so as to hold a photographic film, and an optical waveguide for guiding light emitted from the light source to the photographic film held by the film carrier. The shape and a structure of the film carrier are determined according to the type of photographic film. The film carrier is detachably disposed in a film carrier supporting portion provided at the main body of the image reading apparatus, and a photographic film is loaded in the film carrier. Here, the film carrier supporting portion can support any film carrier corresponding to the type of photographic film in order to facilitate operation of changing the type of photographic film from which an image is read. The shape and structure of the optical waveguide are also determined according to the type of photographic film. The optical waveguide corresponding to the type of photographic film with an image to be read recorded thereon is replaceably fixed at the main body of the image reading apparatus. Consequently, a film carrier and optical waveguide which both corepond to the same type of photographic film must always be used in combination.
In the case where in the conventional image reading apparatus either one of the mirror box and the film carrier is displaced from the optical axis of the lens unit after the optical axis adjusting operation, the positions of the mirror box, the light source and the film carrier must be adjusted in sequence. Therefore, the conventional image reading apparatus first encounters the problem that the optical axis adjusting operation has a large number of processes and is cumbersome.
Second, in the case where in the conventional image reading apparatus the type of photographic film for which the film carrier is suited is different from that for which the optical waveguide is suited, i.e., in the case where the optical waveguide previously fixed at the main body of the image reading apparatus is erroneously combined with the film carrier disposed in the film carrier supporting portion, the image recorded on the photographic film cannot be read correctly, and further, the apparatus may be broken. Particularly, since the optical waveguides composed of the mirror box and the like suitable for any type of photographic film are formed in a similar extarnal shape, there is a possibility that the film carrier may be disposed in the film carrier supporting portion without the fact that the optical waveguide has been attached in an erroneous combination to the main body of the image reading apparatus being noticed.
In consideration of the above-described problems, a first object of the present invention is to provide a light amount adjusting device in which an optical axis adjusting operation for an optical waveguide and a film carrier can be simplified with respect to an optical axis of an image forming optical system.
Furthermore, in consideration of the above-described problems, a second object of the present invention is to provide an image reading apparatus which can be prevented from being broken if an optical waveguide previously fixed to the apparatus and a film carrier to be disposed in a film carrier supporting portion are incorrectly combined, and further, which can inform an operator of the incorrect combination of the optical waveguide previously fixed to the apparatus and the film carrier to be disposed in the film carrier supporting portion.
In order to attain the aforementioned first object, the image reading apparatus according to the present invention comprises: a light source for irradiating light onto a photographic photosensitive material; an image forming optical system for forming reflected or transmitted light from the photographic photosensitive material into an image; a film carrier for supporting the photographic photosensitive material loaded from the outside; an optical waveguide for guiding the light, which is incident on an incident light portion from the light source, to a light emitting portion, and irradiating the light from the light emitting portion onto the photographic photosensitive material supported by the film carrier in such a manner that the reflected or transmitted light from the photographic photosensitive material is incident into the image forming optical system; and a supporting/positioning member interposed between the light source and the image forming optical system, for supporting the film carrier and the optical waveguide.
In the image reading apparatus having the above-described configuration, both the film carrier and the optical waveguide are supported by the supporting/positioning member, thus suppressing a relative displacement of either one of the film carrier and the optical waveguide disposed in the supporting/positioning member from the other. Consequently, after the positions of the film carrier and the optical waveguide together with the supporting/positioning member are adjusted to respective predetermined positions on the optical axis of the image forming optical system, it is possible to suppress a displacement of only one of the film carrier and the optical waveguide from the optical axis of the image forming optical system. Furthermore, it is possible to restrict the displacement of the film carrier or the optical waveguide to a slight amount in the case where only one of the film carrier and the optical waveguide is displaced from the optical axis of the image forming optical system.
If the supporting/positioning member is moved in the direction perpendicular to the optical axis, the film carrier and the optical waveguide together with the supporting/positioning member are moved integrally with each other without any change in the relative position thereof. Consequently, the positions of the film carrier and the optical waveguide can be adjusted at the same time just by the position adjusting operation of the supporting/positioning member, thereby simplifying the optical axis adjusting operation for adjusting the positions of the film carrier and the optical waveguide to their respective predetermined positions on the optical axis of the image forming optical system.
Here, although the supporting/positioning member may have either an integral structure or an assembed structure composed of a plurality of component parts capable of being disassembled, the supporting/positioning member must be able to position the film carrier and the optical waveguide at the respective predetermined positions with the required accuracy, and must have the dimensional accuracy and sufficient strength to prevent any displacement of the film carrier and the optical waveguide after positioning. The image forming optical system forms reflected light or transmitted light from a photographic film into an image on a sensing portion of a reading sensor such as a CCD (charge couple device) image sensor or on photographic paper. At this time, the reading sensor or the photographic paper is positioned in advance at a predetermined position on the optical axis of the image forming optical system. Consequently, if the reflected light or transmitted light from the photographic film is not incident on a predetermined incident position of the image forming optical system, a deviation may be generated in an image point in the image forming optical system, whereby a normal reproduced image cannot be obtained.
The image reading apparatus according to the present invention may preferably comprise movable supporting means for supporting the supporting/positioning member in such a manner that the position of the supporting/positioning member can be adjusted in a direction perpendicular to the optical axis of the image forming optical system.
In the image reading apparatus having the above-described configuration, the movable supporting means supports the supporting/positioning member in such a manner as to adjust the position of the supporting/positioning member in the direction perpendicular to the optical axis of the image forming optical system. Therefore, if the relative position of the film carrier and the optical waveguide are adjusted in advance on the supporting/positioning member to a predetermined positional relationship, the film carrier and the optical waveguide can be adjusted to their respective predetermined positions on the optical axis of the image forming optical system at the same time simply of the position adjusting operation of the supporting/positioning member of the movable supporting means without independent positional adjustment of the film carrier and the optical waveguide, thus simplifying the optical axis adjusting operation with respect to the film carrier and the optical waveguide.
In the image reading apparatus according to the present invention, it is preferable that the optical waveguide and the film carrier should be detachably disposed in the supporting/positioning member.
In the image reading apparatus having the above-described configuration, the film carrier and the optical waveguide are detachably disposed in the supporting/positioning member, thereby simplifying the operation of replacing the film carrier and the optical waveguide. Furthermore, if the supporting/positioning member, the optical waveguide and the film carrier have sufficiently high dimensional accuracy within the positioning error allowable at the time of optical axis adjustment, it is possible to suppress a change in the relative positions of either one of the film carrier and the optical waveguide to the other to a slight level even after the replacement of the film carrier and the optical waveguide in the supporting/positioning member, thus dispensing with the independent position adjusting operation of the film carrier and the optical waveguide after the replacement.
Namely, it is necessary to use a special film carrier and a special optical waveguide exclusive to the type of photographic film. If the type of photographic photosensitive material (photographic film) for reading an image is changed, the optical waveguide and the film carrier already disposed in the supporting/positioning member are detached, and then, a film carrier and an optical waveguide exclusive to the type of photographic film must then be disposed in the supporting/positioning member. However, according to the present invention, it is possible to reduce the time required for the replacing operation of the film carrier and the optical waveguide.
Here, the term photographic film refers to a film in which a negative or positive image becomes visualized after an object is photographed, followed by development. The types of photographic film include, for example, a photographic film of a 135 size, a photographic film of 110 size, a photographic film with a transparent magnetic layer formed thereon (i.e. a photographic film of 240 size, known as an APS film) and photographic films of 120 and 220 sizes (Brownie sizes). These films are different in the film width in the transverse direction thereof, in the shape of the image recording region, in size, and in structure. Therefore, the film carrier and the optical waveguide must have the structure and shape to correspond to the type of photographic film.
In order to attain the aforementioned second object, the image reading apparatus according to the present invention can read images from a plurality of types of photographic films, and further, the image reading apparatus comprises:
a film carrier, having a shape corresponding to the type of photographic film, for holding the photographic film;
a film carrier supporting portion, in which the film carrier is detachably disposed, for positioning the photographic film held by the film carrier at a predetermined reading position;
an optical waveguide being replaceably fixed to a predetermined reference fixing position and having a shape corresponding to the type of photographic film, for irradiating light emitted from a light source onto the reading position; and
a retracting means for moving the optical waveguide from the reference fixing position by pressing force of the film carrier disposed in the film carrier supporting portion in the case where the shapes of the film carrier and the optical waveguide are not suited for the type of photographic film.
In the image reading apparatus having the above-described configuration, in the case where the film carrier and the optical waveguide for the different types of photographic films are provided, i.e., in the case where the film carrier and the optical waveguide are combined incorrectly, the retracting means is pressed by the film carrier disposed in the film carrier supporting portion, so that the optical waveguide is moved from the reference fixing position. Consequently, it is possible to prevent a heavy load from acting on the film carrier and the optical waveguide even if the film carrier disposed in the film carrier supporting portion abuts against the optical waveguide or the like. Thus, it is possible to prevent any breakage of the film carrier, the optical waveguide and the members on which the load is exerted via the film carrier or the optical waveguide.
Here, the retracting means receives directly or indirectly the pressurizing force from the film carrier disposed in the film carrier supporting portion, to thus move the optical waveguide and/or its supporting portion in a direction retracting from the film carrier in the case of the incorrect combination of the film carrier and the optical waveguide.
In the image reading apparatus according to the present invention, the retracting means may preferably comprise:
an urging member for urging the optical waveguide moved by the pressing force of the film carrier in the direction of the reference attachment position; and
a stopper member for stopping the optical waveguide moved by urging force of the urging member at the reference attachment position when the film carrier is detached from the film carrier supporting portion.
In the image reading apparatus having the above-described configuration, the optical waveguide is moved by the film carrier disposed in the film carrier supporting portion in the case of the incorrect combination of the film carrier and the optical waveguide. However, when the film carrier is detached from the film carrier supporting portion, the optical waveguide is automatically returned to the reference fixing position, thus dispensing with a returning operation for returning the film carrier moved in the retracting direction to the reference fixing position.
The image reading apparatus according to the present invention may preferably comprise a retract detecting means for detecting that the optical waveguide is moved by the pressing force of the film carrier.
In the image reading apparatus having the above-described configuration, when the optical waveguide is moved by the pressing force of the film carrier, this fact is detected by the retract detecting means. Consequently, an alarm can be output during the detection by the retract detecting means. This alarm can inform an operator or the like of the incorrect combination of the film carrier and the optical waveguide when the film carrier is disposed in the film carrier supporting portion. Moreover, it is possible to interlock-control the apparatus in such a manner as not to perform reading of the photographic film during the detection by the retract detecting means, so as to prevent any reading of the photographic film in the case of the incorrect combination of the film carrier and the optical waveguide.
Here, the retreat detecting means is constituted of, e.g., a micro switch or a photoelectric or magnetic proximity sensor, and is adapted to detect the movement of the optical waveguide in the retracting direction: it is configured such that it is turned on by the optical waveguide located at the reference fixing position while it is turned off when the optical waveguide is separated from the reference fixing position; or it is turned off when the optical waveguide is located at the reference fixing position while it is turned on by the optical waveguide moved from the reference fixing position toward the retracting direction. Furthermore, the alarm output during the detection by the retract detecting means includes means by the use of sound generated by a buzzer or the like, light by a lamp or the like, or characters, symbols or images displayed on a display or the like.